Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
1162772 | Analytica Chimica Acta | 2016 | 9 Pages |
•QD-MIP composites were first built on a glass substrate through a sol–gel route.•Two silanes were evaluated as both a surface modifier and a functional capping monomer.•Fluorescence enhancement by template on glass was different from quenching in solution.
A fluorescence-based sensor that combines the merits of quantum dots (QDs) and molecularly imprinted polymers (MIPs) was first fabricated on a glass substrate via a sol–gel route. Some of the key performance factors, including silane selection, substrate etching, the reaction times of glass silanization and sol–gel polymerization, and the times and methods used for template stripping and loading, were discussed and determined. After fabricating the sensor on either a 3-aminopropyltriethoxysilane (APS) or a 3-mercaptopropyltriethoxysilane (MPS) modified glass substrate, APS showed a much better performance than MPS as both the capping reagent of QDs and the functional monomer of tetracycline-templated MIPs. The APS-QDs on APS-modified glass had a higher imprinted factor (IF = 5.6), a lower LOD (2.1 μM, 3σ), and a more stable signal (2.8%, n = 10 at 70 μM) than those on the MPS-modified glass (IF = 5.2, LOD = 6.5 μM, stability = 6.2%). Furthermore, the recoveries of tetracycline (70 μM) from BSA (133 μg/mL) and FBS (0.66 ppt) by the APS-modified glass were 98% (RSD = 3.5%, n = 5) and 97% (RSD = 5.7%), respectively. For the MPS-modified glass, recoveries of 95% (RSD = 7.2%) and 89% (RSD = 8.7%) were observed at 67 μg/mL of BSA and 0.33 ppt of FBS, respectively.
Graphical abstractFigure optionsDownload full-size imageDownload as PowerPoint slide